Peripheral circuit of touch panel and manufacturing method thereof

ABSTRACT

A method for manufacturing a peripheral circuit of a touch panel includes: printing a radiation curable conductive material on a substrate having a transparent conductive pattern; irradiating the radiation curable conductive material with a radiated ray, in order to cure parts of the radiation curable conductive material; and removing uncured parts of the radiation curable conductive material, in order to form the peripheral circuit.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of application Ser. No. 13/858,913,filed on Apr. 8, 2013 and entitled “PERIPHERAL CIRCUIT OF TOUCH PANELAND MANUFACTURING METHOD THEREOF”, the contents of which areincorporated herein in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a peripheral circuit of a touch paneland a manufacturing method thereof.

2. Description of the Prior Art

Various types of touch technology are widely applied in electronicproducts. For example, in mobile phones and tablets, touch panels areoften utilized as an input interface. The user can use their hand todirectly contact the surface of the touch panel for performingoperations, or slide their hand on the surface of the touch panel tocontrol a mouse or perform a hand-written input. A display together withthe touch panel may also show a virtual keyboard for the user, and theuser can input characters via corresponding keys on the virtualkeyboard.

The touch panel may be divided into various types such as a resistivetouch panel, capacitive touch panel, ultrasonic touch panel and infraredray touch panel. Among these touch panels, the resistive touch panel isthe most commonly utilized. The resistive touch panel may mainly bedivided into a four-wire touch panel, five-wire touch panel, six-wiretouch panel and eight-wire touch panel. Since the four-wire touch panelis more mature in consideration of cost and technology, it is currentlythe most widely manufactured. The capacitive touch panel, however, cansense a light-touch, and thus is more convenient for utilization. Inaddition, the capacitive touch panel rarely wears down due to fingercontact. It is also more stable and has a longer life than the resistivetouch panel. For these reasons, the capacitive touch panel is graduallyreplacing the resistive touch panel as the most commonly utilized touchpanel applied in electronic products.

The touch panel includes a substrate, a transparent conductive layerformed on the substrate, a peripheral circuit and an insulating layer.The touch panel may further include a connected flexible printed circuitboard (FPC). The peripheral circuit is connected with the transparentconductive layer and the FPC. The peripheral circuit can be formed by aphotolithography process. The conventional photolithography processincludes the following steps: first, a metal layer is formed on thesubstrate by deposition or electrode planting; then a photoresist layeris applied on the metal layer, and selective exposure is performed onthe photoresist layer; then developing is performed on the photoresistlayer after exposure with a developer, to obtain a patterned photoresistlayer; finally, the patterned photoresist layer is utilized as a mask toetch the metal layer, in order to form a conductive circuit on thesubstrate.

When the conventional photolithography process is implemented, the stepsare complex and need to utilize a large number of chemicals, such thatthe cost is high and the process may not comply with the requirementsand trends of environmental protection emphasized in modern science andtechnology.

In order to solve the problems of manufacturing the peripheral circuitwith the conventional photolithography process, the industry provides amanufacturing method for forming the peripheral circuit with a printingprocess. This method prints a thermal setting conductive adhesive on thesubstrate, and then cures and bakes the thermal setting conductiveadhesive with a high temperature, in order to form the peripheralcircuit. This manufacturing method benefits from a simplified process incomparison to the photolithography process, but the peripheral circuitformed by utilizing the printing process may come off since theadherence degree of the printing ink connected with the substrate islow, which causes the conductive circuit to be cut off. In addition,this method may only be applied in a conductive pattern and circuit witha thicker wire width and a greater wire distance, and cannot effectivelyenhance the density of circuit disposition.

Therefore, how to provide a peripheral circuit of a touch panel and amanufacturing method thereof which are capable of reducing wire width orwire distance in order to achieve higher integration while complyingwith environmental protection requirements becomes an important issue.

SUMMARY OF THE INVENTION

It is an objective of the present invention to provide a peripheralcircuit of a touch panel that can be manufactured using a simplifiedprocess while maintaining the adherence degree and electroniccharacteristics, and a manufacturing method thereof, which can reducewire width or wire distance in order to achieve higher integration whilecomplying with environmental protection requirements.

In order to achieve the above objectives, a method of manufacturing aperipheral circuit of a touch panel according to the present inventioncomprises the following steps: printing a radiation curable conductivematerial on a substrate having a transparent conductive pattern;irradiating the radiation curable conductive material with a radiatedray, in order to cure parts of the radiation curable conductivematerial; and removing uncured parts of the radiation curable conductivematerial, in order to form the peripheral circuit.

According to an embodiment of the present invention, a wavelength of theradiated ray is approximately within a range from 230 nanometers to 600nanometers.

According to an embodiment of the present invention, the transparentconductive pattern is connected with the peripheral circuit.

According to an embodiment of the present invention, a wire width of theperipheral circuit is less than or equal to about 70 micrometers.

According to an embodiment of the present invention, the radiationcurable conductive material comprises radiation curable silver glue,radiation curable silver paste or radiation curable ink.

According to an embodiment of the present invention, the step of curingparts of the radiation curable conductive material comprises selectivelycuring the radiation curable conductive material by disposing aphotomask on the radiation curable conductive material, wherein amaterial of the photomask comprises glass, quartz or polyethyleneterephthalate (PET).

According to an embodiment of the present invention, the radiated rayirradiates the radiation curable conductive material with at least twodifferent wavelength ranges.

According to an embodiment of the present invention, the radiationcurable conductive material is printed on the substrate by screenprinting.

According to an embodiment of the present invention, the substrate is atransparent plastic substrate, a transparent glass substrate or a PETthin film substrate.

In order to achieve the above objectives, a touch panel according to thepresent invention comprises a substrate and a peripheral circuit. Thesubstrate has a transparent conductive pattern. The peripheral circuitis connected with the transparent conductive pattern. A material of theperipheral circuit comprises a radiation curable conductive material.

According to an embodiment of the present invention, a wire width of theperipheral circuit is less than or equal to about 70 micrometers.

According to an embodiment of the present invention, the radiationcurable conductive material comprises radiation curable silver glue,radiation curable silver paste or radiation curable ink.

According to an embodiment of the present invention, the substrate is atransparent plastic substrate, a transparent glass substrate or a PETthin film substrate.

In order to achieve the above objectives, a peripheral circuit of atouch panel according to the present invention is manufactured using theabove methods.

In order to achieve the above objectives, a method of manufacturing aperipheral circuit of another touch panel according to the presentinvention comprises the following steps: printing a photosensitiveconductive material on a substrate by screen printing; disposing aphotomask on the photosensitive conductive material; irradiating thephotosensitive conductive material with a beam, in order to cure partsof the photosensitive conductive material; and etching uncured parts ofthe photosensitive conductive material, in order to form the peripheralcircuit.

According to an embodiment of the present invention, the substrate is atransparent substrate.

According to an embodiment of the present invention, the photosensitiveconductive material comprises a plurality of silver particles, and adiameter of the plurality of silver particles is within a range from 1micrometer to 10 micrometers.

According to an embodiment of the present invention, a wire width of theperipheral circuit is less than 100 micrometers.

According to an embodiment of the present invention, a material of thephotomask comprises glass, quartz or PET.

According to an embodiment of the present invention, the step of etchingis performed by wet etching.

According to an embodiment of the present invention, the method furthercomprises connecting the peripheral circuit with a flexible printedcircuit board (FPC) by using a conductive adhesive.

According to an embodiment of the present invention, the conductiveadhesive is an anisotropic conductive film (ACF) or anisotropicconductive paste (ACP).

According to an embodiment of the present invention, the method furthercomprises disposing a protective film on the peripheral circuit.

According to an embodiment of the present invention, the step ofdisposing the protective film on the peripheral circuit comprisesdisposing the protective film utilizing a pasting method or a printingmethod.

According to an embodiment of the present invention, the beam comprisesa visible light with a wavelength within a range from 350 micrometers to780 micrometers.

As mentioned above, the peripheral circuit of the touch panel and themanufacturing method thereof according to one exemplary embodiment ofthe present invention utilizes radiation curable conductive material asa printing material to be printed on the substrate, cures parts of theradiation curable conductive material, and then removes uncured parts ofthe radiation curable conductive material in order to form theperipheral circuit. These steps can realize the reduction of wire widthor wire distance in order to achieve higher integration while complyingwith environmental protection requirements. The peripheral circuit ofthe touch panel and the manufacturing method thereof according toanother exemplary embodiment of the present invention utilizesphotosensitive conductive material as a printing material to be printedon the substrate, cures parts of the photosensitive conductive material,and then etches uncured parts of the photosensitive conductive materialin order to form the peripheral circuit. These steps can realize thesimplification of the manufacturing process while retaining theadherence degree and electronic characteristics. For the implementationof the present invention, the manufacturing method enjoys the benefitsof screen printing and exposure/development; hence power consumptionproblems can be avoided, as opposed to the conventional thermal curingprocess where the power consumption is generated by using an oven for along time. Therefore, the environmental protection requirements can alsobe met.

In summary, the peripheral circuit of the touch panel and themanufacturing method thereof according to the present invention enjoythe benefits of screen printing and exposure/development, which not onlycan manufacture the touch panel at a low cost and high speed, but canalso provide the touch panel with the advantages of small wire width andwire distance. This method is therefore suitable for smaller electronicdevices. The peripheral circuit of the touch panel and the manufacturingmethod thereof according to the present invention can enlarge thevisible area, which provides greater convenience for the user.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A and FIG. 1B are schematic diagrams of a touch panel according toa preferable embodiment of the present invention.

FIG. 2A and FIG. 2B are schematic diagrams of another touch panelaccording to a preferable embodiment of the present invention.

FIG. 3 is a block diagram of a method of manufacturing the peripheralcircuit of the touch panel according to a preferable embodiment of thepresent invention.

FIG. 4A to FIG. 4D are schematic diagrams of another touch panelaccording to a preferable embodiment of the present invention.

FIG. 5 is a block diagram of a method of manufacturing the peripheralcircuit of the touch panel according to a preferable embodiment of thepresent invention.

FIG. 6A and FIG. 6B are schematic diagrams of another touch panelaccording to a preferable embodiment of the present invention.

DETAILED DESCRIPTION

In the following, the description refers to illustrations related to aperipheral circuit of a touch panel and a manufacturing method thereofaccording to preferable embodiments of the present invention, where thesame elements are denoted by the same reference symbols.

Please refer to FIG. 1A and FIG. 1B, which are schematic diagrams of atouch panel 1 according to a preferable embodiment of the presentinvention. The touch panel 1 includes a substrate 11 and a peripheralcircuit 12. The substrate 11 can be, for example, a transparent plasticsubstrate or a transparent glass substrate. In addition, the substrate11 can also be a polyethylene terephthalate (PET) thin film substrate orother thin film-shaped substrates. The substrate 11 has an outer surfaceS1 and an inner surface S2. The user usually views the touch panel 1from the outer surface S1 side, and performs various kinds of operationson the outer surface S1. Other structures and elements of the touchpanel 1 are disposed on the inner surface S2 side of the substrate 11.

The inner surface S2 of the substrate 11 includes a transparentconductive pattern 111, a masking decoration layer 112 and a conductivelayer 113. The transparent conductive pattern 111, disposed on the innersurface S2 of the substrate 11, is utilized for defining a touch sensingcircuit. The material of the transparent conductive pattern 111 can be,for example, indium tin oxide (ITO). The masking decoration layer 112 isdisposed next to a terminal of the transparent conductive pattern 111,and the material of the masking decoration layer 112 can be, forexample, an insulating material or insulating ink with various colors.The conductive layer 113 is disposed on the masking decoration layer 112and the transparent conductive pattern 111, and extends from a terminalof the transparent conductive pattern 111 to the masking decorationlayer 112. The material of the conductive layer 113 includes atransparent high molecular conductive material or ITO, and theconductive layer 113 maybe formed on the masking decoration layer 112and the transparent conductive pattern 111 by printing.

The peripheral circuit 12 is disposed on the conductive layer 113 andthe masking decoration layer 112, and extends to the conductive layer113 without exceeding an edge of the masking decoration layer 112. Inother words, projection of the peripheral circuit 12 is located on themasking decoration layer 112, or is flush with the edge of the maskingdecoration layer 112. The material of the peripheral circuit 12 is aradiation curable conductive material, which can be, for example,radiation curable silver glue, radiation curable silver paste orradiation curable ink. Fine circuits of the peripheral circuit 12 aredefined by using screen printing equipment together with a screen withfine wires, and are formed on the transparent conductive pattern 111 andthe masking decoration layer 112 by printing. Please note that, in theabove process, the radiation curable conductive material may preferablybe disposed as block-shaped circuits on the substrate printed directlyby the printing equipment. In this process, no fine wire mesh needs tobe utilized, and the printed block-shaped circuits may further beutilized for forming finer circuits in cooperation with lithographytechnique. Such implementation allows the wire width of the peripheralcircuit 12 to be less than or equal to 70 micrometers, and reduces therequirements for high precision screens, which favors cost reduction andquality enhancement. The following paragraphs will detail how tocooperate with the lithography technique, and the photolithographytechnique in particular.

The above radiation curable conductive material is not limited to becomposed of some special elements. The radiation curable conductive canbe a material which has a certain conductivity and will be dried orcured after being irradiated by a short wavelength radiated ray.Specifically, the radiation curable conductive material can be anultraviolet radiation cured conductive material or an ultravioletradiation dried conductive material, which is liquid or adherent whenprinted, where parts of the material which are irradiated by theultraviolet radiation will be dried or cured immediately and adhered tothe substrate. The non-irradiated parts will still be liquid oradherent, and can be removed easily. In addition, conductive materialswhich are dried or cured when irradiated by radiated rays with otherwavelengths may also be utilized. The above is therefore not limited toultraviolet radiation.

As shown in FIG. 1B, the touch panel 1 may further include an insulatinglayer 13 and a conductive adhesive 14. The insulating layer 13 coversparts of the peripheral circuit 12 by screen printing, in order toprevent the peripheral circuit 12 from being oxidized due to exposure tothe air. The conductive adhesive 14 is adhered to the peripheral circuit12 and a pin P of a flexible printed circuit board (FPC), such that thetouch sensing signals generated by the transparent conductive pattern111 can be transmitted to the pin P of the FPC via the conductive layer113, the peripheral circuit 12 and the conductive adhesive 14. In otherembodiments, the conductive adhesive 14 may be an anisotropic conductivefilm (ACF) or anisotropic conductive paste (ACP). When the touch panelis applied, the insulating layer may also be ignored, which is notlimited herein.

Please note that the transparent conductive pattern 111 in thisembodiment is formed on the substrate 11 directly, and the substrate 11belongs to a type having touch sensing functions and a cover platesimultaneously. The application is not limited to this, and varioustypes of touch panels can be applied according to the present invention.For example, a substrate with a two-layer structure composed of twosubstrates may also be applied in the present invention, where the toplayer substrate and the bottom layer substrate both possess thetransparent conductive pattern.

Please refer to FIG. 2A and FIG. 2B, which are schematic diagrams ofanother touch panel 2 according to a preferable embodiment of thepresent invention. The touch panel 2 includes a substrate 21 and aperipheral circuit 22. The substrate 21 can be a transparent substrate,which can be, for example, a plastic substrate or a glass substrate. Thesubstrate 21 may also be other types such as a PET thin film substrateor other thin film-shaped substrates. The user usually views the touchpanel 2 from the outer surface S1 side of the substrate 21 and performsvarious kinds of operations on the outer surface S1. Other structuresand elements of the touch panel 2 are disposed on the inner surface S2side of the substrate 21.

The inner surface S2 of the substrate 21 includes a transparentconductive pattern 211, a masking decoration layer 212 and a conductivelayer 213. The transparent conductive pattern 211 is utilized fordefining a touch sensing circuit. The material of the transparentconductive pattern 211 can be, for example, ITO. The conductive layer213 is disposed on the substrate 21, and extends to a terminal of thetransparent conductive pattern 211 to cover parts of the transparentconductive pattern 211. The masking decoration layer 212 is disposed onthe substrate 21 and the conductive layer 213 and extends to theconductive layer 213. The masking decoration layer 212 possesses anopening H on the conductive layer 213, where the masking decorationlayer 212 is disposed without exceeding an edge of the conductive layer213.

The material of the conductive layer 213 includes conductive carbonpaste, and the material of the masking decoration layer 212 can be, forexample, an insulating material or insulating ink with various colors.For color selection of the masking decoration layer 212, a color similarto that of the conductive layer 213 is preferably selected to beutilized, such that the user may not feel the difference of colorbetween the masking decoration layer 212 and the conductive layer 213when viewing the outer surface S1 of the touch panel 2. In addition, theconductive layer 213 and the masking decoration layer 212 may be formedon the substrate 21 by printing.

The peripheral circuit 22 is disposed on the masking decoration layer212, and a part of the peripheral circuit 22 is filled in the opening Hand coupled to the conductive layer 213. The material of the peripheralcircuit 22 is a radiation curable conductive material, which can be, forexample, radiation curable silver glue, radiation curable silver pasteor radiation curable ink. The peripheral circuit 12 is formed on themasking decoration layer 212 by printing and irradiating of a radiatedray.

As shown in FIG. 2B, the touch panel 2 further includes an insulatinglayer 23 and a conductive adhesive 24. The insulating layer 23 isdisposed on the peripheral circuit 22, in order to prevent theperipheral circuit 22 from being oxidized due to exposure to the air.The conductive adhesive 24 is adhered to the peripheral circuit 22 and apin P of an FPC. The pin P is coupled to the conductive layer 213 viathe conductive adhesive 24 and the peripheral circuit 22, in order toreceive the touch sensing signals generated by the transparentconductive pattern 211, where the conductive adhesive 24 can be ACF orACP. In other embodiments, the insulating layer may also be ignored,which is not limited herein.

Please refer to the block diagram shown in FIG. 3 together with FIG. 1A,which illustrates a method of manufacturing the peripheral circuit ofthe touch panel according to a preferable embodiment of the presentinvention. This method can be applied for manufacturing theabovementioned peripheral circuit 12 of the touch panel 1. The steps ofthe manufacturing method include Steps S31-S33.

Step S31 is printing a radiation curable conductive material on thesubstrate 11 having the transparent conductive pattern 111. For theimplementation of Step S31, at least two methods may be included. One ofthe methods is forming the radiation curable conductive material on thetransparent conductive pattern 111 and the masking decoration layer 112of the substrate 11 by printing (especially screen printing) by usingscreen printing equipment in cooperation with a fine wire mesh, whereinthe fine wires printed on the radiation curable conductive material areprocessed by follow-up radiation, in order to form the finer peripheralcircuit 12. The second preferable method is printing the radiationcurable conductive material on the substrate 11 directly by blocks orareas where the fine wire mesh is not utilized, and the follow-upoperations are then performed on the formed pattern, in order to form aplurality of wires of the peripheral circuit 12.

The abovementioned radiation curable conductive material can beradiation curable silver glue, radiation curable silver paste orradiation curable ink. The substrate 11 is a transparent substrate,which can be, for example, a plastic substrate or a glass substrate. Inother cases, the substrate 11 may also be PET thin film substrate orother thin film-shaped substrates. The material of the transparentconductive pattern 111 can be, for example, ITO, and the material of themasking decoration layer 112 can be, for example, an insulating materialor insulating ink with various colors. The transparent conductivepattern 111 may first be formed on the substrate 11 by sputtering andetching, and the masking decoration layer 112 may be disposed on thesubstrate 11 by deposition or printing according to its material.

Step S32 is irradiating the radiation curable conductive material with aradiated ray, in order to cure parts of the radiation curable conductivematerial. For the implementation of Step S32, the radiation curableconductive material is irradiated by a radiated ray having a wavelengthwithin a range from 230 nanometers to 600 nanometers. In order toregulate the position of the circuit layout, the method for curing partsof the radiation curable conductive material is performed by disposing aphotomask on the radiation curable conductive material, which allows theradiated ray to cure the radiation curable conductive materialselectively according to product requirements or circuit designs. Thematerial of the above photomask includes glass, quartz or PET, and theform of photomask can be, but is not limited to, positive or negative,which is determined according to the nature of the material and thestructural requirements of the peripheral circuit 12.

In order to enhance the integration of the radiation curable conductivematerial connected with the transparent conductive pattern 111 and themasking decoration layer 112, and accelerate the speed for curing theradiation curable conductive material, the radiated ray may irradiatethe radiation curable conductive material in at least two phases. Duringthese two phases of irradiation, the radiated ray may have two differentwavelength ranges. For example, the radiation curable conductivematerial may first be irradiated by the radiated ray with a wavelengthrange from 300 nanometers to 400 nanometers, and then be irradiated bythe radiated ray with a wavelength range from 230 nanometers to 600nanometers. Please note that the above wavelength ranges are only anexemplary illustration, and are not utilized for limiting the presentinvention.

Step S33 is removing uncured parts of the radiation curable conductivematerial, in order to form the peripheral circuit 12. For theimplementation of Step S33, the uncured parts of the radiation curableconductive material maybe removed by, for example, pure water, such thatthe peripheral circuit 12 can be formed by the cured parts of theradiation curable conductive material. The peripheral circuit 12 isconnected with the transparent conductive pattern 111, and transmits thetouch sensing signals generated by the transparent conductive pattern111 to an FPC. Since printing and parts of the photolithography processare integrated according to the present invention, the peripheralcircuit 12 can be manufactured in an easy and low cost way, and theformed wire width can be less than or equal to about 70 micrometers,which enhances the integration. The utilization of a large number ofchemicals is excluded in the present invention, which not onlysimplifies the process significantly, but also complies withenvironmental protection and power saving.

The peripheral circuit 22 of the other touch panel 2 provided by thepresent invention may also be manufactured by the above methods, andboth the structure characteristics and the process can be known byreferring to the above illustration. These will not be narrated herein.

The above peripheral circuit of the touch panel and the manufacturingmethod thereof according to the present invention utilizes radiationcurable conductive material as a printing material to be printed on thesubstrate, cures parts of the radiation curable conductive material, andthen removes uncured parts of the radiation curable conductive materialin order to form the peripheral circuit, which realizes the reduction ofwire width or wire distance in order to achieve higher integration whilecomplying with environmental protection requirements. In addition toutilizing the radiation cured material as the above conductive material,other types of conductive materials may also be realized. What followsis an embodiment utilizing a photosensitive material as the conductivematerial, which is cured by a visible light in order to form theperipheral circuit.

Please refer to FIG. 4A, which is a schematic diagram of a further touchpanel 4 according to a preferable embodiment of the present invention.The touch panel 4 includes a substrate 41 and a peripheral circuit 42.The substrate 41 is a transparent substrate, which can be, for example,a plastic substrate or a glass substrate. In other embodiments, thesubstrate 41 may also be a thin film-shaped substrate such as a PET thinfilm, etc. In order to take advantage of the exposure and developmentprocess in which a high temperature baking process is not required, thesubstrate 41 can preferably be a thin film substrate having flexibility,which is called a flexible substrate, but is not limited herein.

The substrate 41 has an outer surface S1 and an inner surface S2. Theuser usually views the touch panel 4 from the outer surface S1 side ofthe substrate 41, and performs various kinds of operations on the outersurface S1. Other structures and elements of the touch panel 4 aredisposed on the inner surface S2 side of the substrate 41. In thisembodiment, the inner surface S2 of the substrate 41 includes atransparent conductive layer 411. The transparent conductive layer 411is utilized for defining a touch sensing circuit, and the material ofthe transparent conductive layer 411 can be, for example, ITO.

The peripheral circuit 42 is disposed on the inner surface S2 of thesubstrate 41, and is placed next to a terminal of the transparentconductive layer 411 by screen printing. The material of the peripheralcircuit 42 is a photosensitive conductive material, which includes aphotosensitive resin composition and a plurality of silver particles.For the implementation of the peripheral circuit 42, a diameter of thesilver particles is within a range from 1 micrometer to 10 micrometers,and more preferably, within a smaller range from 1 micrometer to 5micrometers; it may also be blended with several nanometer silverparticles. In addition, the photosensitive resin composition is amaterial which may react after being irradiated by a light.

As shown in FIG. 4B, the touch panel 4 may further include an insulatinglayer 43, a conductive adhesive 44 and an FPC 45. The insulating layer43 is formed on parts of the peripheral circuit 42 by pasting orprinting, in order to prevent the peripheral circuit 42 from beingoxidized due to exposure to the air. The color of the insulating layer43 may also be selected according to product requirements, which allowsthe insulating layer 43 to be a decoration layer simultaneously. Theconductive adhesive 44 is adhered to the peripheral circuit 42 and a pin451 of the FPC 45, such that the touch sensing signals generated by thetransparent conductive layer 411 can be transmitted to the pin 451 ofthe FPC 45 via the peripheral circuit 42 and the conductive adhesive 44.In some embodiments, the conductive adhesive 44 can be ACF or ACP.

Please note that, in this embodiment, the transparent conductive layer411 is formed on the substrate 41 directly and provides touch sensingfunctions independently; hence the substrate 41 in this embodimentbelongs to a type having touch sensing functions and a cover platesimultaneously. According to the present invention, a two-layer touchpanel 4c with a two-layer structure may also be utilized, where thetwo-layer touch panel 4c is composed of two substrates 41, asillustrated in FIG. 4C. The following paragraphs illustrate that theabove substrate 41 with one-layer structure includes multiple functions.

After the assembly process of the substrate 41 is accomplished, only theouter surface S1 of the substrate 41 is exposed to the outside, and thetransparent conductive layer 411, the peripheral circuit 42 and otherstructures are covered by the substrate 41. In such a condition, thesubstrate 41 not only can provide decoration functions and cover theseelements such as the peripheral circuit 42, etc., but can also protectthe peripheral circuit 42 and the transparent conductive layer 411 fromdamages. Moreover, the complete transparent conductive layer 411 isdisposed on the substrate 41, which is enough to provide sensingfunctions. Therefore, the present invention realizes both thesimplification of substrate process and the diversification offunctions. This prospective creation of the distinguishing features issuitable for a modular process to benefit from cost reduction.

Please keep referring to FIG. 4D. A touch panel 4d is substantially thesame as the above touch panel 4 shown in FIG. 4B, and the onlydifference is that the touch panel 4d further includes a protective film46. The protective film 46 may be formed on the peripheral circuit 42and the transparent conductive layer 411 by pasting or printing, inorder to cover these two elements and provide protection and decorationfunctions. The protective film 46 can be adhered to the substrate 41stably by adding an optical clear adhesive (OCA) 47.

Please refer to the block diagram shown in FIG. 5 together with FIG. 4A,which illustrates a method of manufacturing the peripheral circuit ofthe touch panel according to a preferable embodiment of the presentinvention. This method can be applied for manufacturing theabovementioned peripheral circuit 42 of the touch panel 4. The steps ofthe manufacturing method include Steps S51-S54.

Step S51 is printing a photosensitive conductive material on thesubstrate 41 by screen printing. As shown in FIG. 6A, for theimplementation of Step S51, a photosensitive conductive material 63 isformed on the transparent conductive layer 411 of the substrate 41 byprinting via screen printing equipment composed of a scraper 61 and ascreen 62. In detail, the screen printing equipment prints thephotosensitive conductive material 63 on the substrate 41 by blocks orareas.

The above photosensitive conductive material 63 includes aphotosensitive resin composition and a plurality of silver particles. Adiameter of the silver particles is within a range from 1 micrometer to10 micrometers, and more preferably within a range from 1 micrometer to5 micrometers. The substrate 41 is a transparent substrate, which canbe, for example, a plastic substrate or a glass substrate. The materialof the transparent conductive layer 411 can be, for example, ITO. Thetransparent conductive layer 411 may first be formed on the substrate 41by sputtering and etching.

Step S52 is disposing a photomask 64 on the photosensitive conductivematerial. In order to regulate the position of the circuit layout, thephotomask 64 is disposed on the photosensitive conductive material 63for the implementation of Step S52, as illustrated in FIG. 6B. Thematerial of the above photomask includes glass, quartz or PET, and theform of the photomask 64 can be, but is not limited to, positive ornegative, which is determined according to the nature of the materialand the structural requirements of the peripheral circuit 42.

Step S53 is irradiating the photosensitive conductive material with abeam 65, in order to cure parts of the photosensitive conductivematerial. For the implementation of Step S53, a light wave generationapparatus is utilized for generating the beam 65, which selectivelyirradiates the photosensitive conductive material 63 via the photomask64, as illustrated in FIG. 6B. The beam 65 can be, for example, avisible light, which has a wavelength within a range from 350 nanometersto 780 nanometers.

Step S54 is etching uncured parts of the photosensitive conductivematerial, in order to form the peripheral circuit 42. For theimplementation of Step S54, for example, developer may be utilized foretching the uncured parts of the photosensitive conductive material, inorder to remove the uncured parts of the photosensitive conductivematerial and form the peripheral circuit 42 with the cured parts of thephotosensitive conductive material. The peripheral circuit 42 isconnected with the transparent conductive layer 411, wherein a wirewidth of the peripheral circuit 42 may be less than 100 micrometers anda wire distance of the peripheral circuit 42 may be less than 120micrometers.

Please refer to FIG. 4D. In this structure, the method of manufacturingthe peripheral circuit of the touch panel 4d further includes: adheringthe peripheral circuit 42 to the FPC 45 by using the conductive adhesive44, and disposing the protective film 46 on the peripheral circuit 42.For the implementation of these steps, the protective film 46 maybeformed on parts of the peripheral circuit 42 and the transparentconductive layer 411 by pasting or printing, in order to prevent theperipheral circuit 42 from being touched or oxidized due to exposure tothe air directly. The color of the protective film 46 may also beselected according to product requirements, which allows the protectivefilm 46 to be a decoration layer simultaneously, in order to prevent theuser from viewing the inside circuits.

The conductive adhesive 44 is adhered to the peripheral circuit 42 andthe pin 451 of the FPC 45, such that the touch sensing signals generatedby the transparent conductive layer 411 can be transmitted to the pin451 of the FPC 45 via the peripheral circuit 42 and the conductiveadhesive 44. In some embodiments, the conductive adhesive 44 can be ACFor ACP.

The above peripheral circuit of the touch panel and the manufacturingmethod thereof according to the present invention utilizesphotosensitive conductive material as a printing material to be printedon the substrate, cures parts of the photosensitive conductive material,and then etches uncured parts of the photosensitive conductive materialin order to form the peripheral circuit, which realizes thesimplification of the manufacturing process while retaining theadherence degree and electronic characteristic.

In summary, the peripheral circuit of the touch panel and themanufacturing method thereof according to the present invention enjoythe benefits of screen printing and exposure/development, ensuring thatnot only can the touch panel be manufactured at a low cost and highspeed, but that the touch panel is also provided with the advantages ofsmall wire width and wire distance. Therefore, this method is suitablefor smaller electronic devices, while overcoming the barriers of theconventional processes. The method of manufacturing the peripheralcircuit of the touch panel utilizing a printing technique according tothe present invention can minimize the wire width and the wire distanceof the peripheral circuit, in order to achieve a fine wire width processto enhance the resolution. The peripheral circuit of the touch panel andthe manufacturing method thereof according to the present invention canalso enlarge the visible area, which provides greater convenience to theuser. For the implementation of the present invention, the manufacturingmethod enjoys the benefits of screen printing and exposure/development;hence power consumption problems can be avoided, as opposed to theconventional thermal curing process where the power consumption isgenerated by using an oven for a long time. Therefore, the environmentalprotection requirements can also be met.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A method for manufacturing a peripheral circuitof a touch panel comprising: printing a radiation curable conductivematerial on a substrate having a transparent conductive pattern;irradiating the radiation curable conductive material with a radiatedray, in order to cure parts of the radiation curable conductivematerial; and removing uncured parts of the radiation curable conductivematerial, in order to form the peripheral circuit.
 2. The method ofclaim 1, wherein a wavelength of the radiated ray is approximatelywithin a range from 230 nanometers to 600 nanometers.
 3. The method ofclaim 1, wherein the transparent conductive pattern is connected withthe peripheral circuit.
 4. The method of claim 1, wherein a wire widthof the peripheral circuit is less than or equal to about 70 micrometers.5. The method of claim 1, wherein the radiation curable conductivematerial comprises radiation curable silver glue, radiation curablesilver paste or radiation curable ink.
 6. The method of claim 1, whereinthe step of curing parts of the radiation curable conductive materialcomprises selectively curing the radiation curable conductive materialby disposing a photomask on the radiation curable conductive material.7. The method of claim 1, wherein the radiated ray irradiates theradiation curable conductive material with at least two differentwavelength ranges.
 8. The method of claim 1, wherein the radiationcurable conductive material is printed on the substrate by screenprinting.
 9. A method for manufacturing a peripheral circuit of a touchpanel comprising: printing a photosensitive conductive material on asubstrate by screen printing; disposing a photomask on thephotosensitive conductive material; irradiating the photosensitiveconductive material with a beam, in order to cure parts of thephotosensitive conductive material; and etching uncured parts of thephotosensitive conductive material, in order to form the peripheralcircuit.
 10. The method of claim 9, wherein the photosensitiveconductive material comprises a plurality of silver particles.
 11. Themethod of claim 10, wherein a diameter of the plurality of silverparticles is within a range from 1 micrometer to 10 micrometers.
 12. Themethod of claim 9, wherein a wire width of the peripheral circuit isless than 100 micrometers.
 13. The method of claim 9, furthercomprising: adhering the peripheral circuit to a flexible printedcircuit board (FPC) by using a conductive adhesive, and the conductiveadhesive is an anisotropic conductive film (ACF) or anisotropicconductive past (ACP).
 14. The method of claim 9, further comprising:disposing a protective film on the peripheral circuit.
 15. The method ofclaim 14, wherein the step of disposing the protective film on theperipheral circuit comprises disposing the protective film utilizing apasting method or a printing method.
 16. The method of claim 9, whereinthe beam comprises a visible light with a wavelength within a range from350 micrometers to 780 micrometers.